Guidance for an aeroassisted orbital transfer vehicle

The use of atmospheric drag for slowing satellite in high energy, high apogee orbits to a lower energy, lower apogee orbit about the Earth is investigated. The high energy orbit is assumed to intercept the Earth's atmosphere. Guidance for the atmospheric phase of the trajectory may be done using the aerodynamic forces generated by the passage through the atmosphere. This research was concerned with the investigation of several methods of guidance during the atmospheric phase to cause a significant reduction in the final velocity as the vehicle leaves the atmosphere. In addition, the velocity direction was controlled to exit to a desired target orbit. Lastly excess aerodynamic lift was used to effect a plane change between the entry orbit plane and the exit orbit plane to achieve a desired orbit plane. The guidance methods were applied to a 3 degree-of-freedom simulation which included an oblate Earth gravity model and a rotating atmosphere. Simulation results were compared on the basis of speed of computation of the guidance parameters and amount of added velocity necessary to achieve the desired orbit

Seasonal Occurrence of Pine Root Collar Weevil, \u3ci\u3eHylobius Radicis\u3c/i\u3e (Coleoptera: Curculionidae), in Red Pine Stands Undergoing Decline

A trapping scheme was devised for sampling the pine root collar weevil, Hylobius radicis, in mature red pine plantations in Wisconsin. Adult weevils were trapped throughout the 1986 field season, and the method appears sensitive enough to discern temporal and spatial trends. The number of weevils caught was higher in stands symptomatic of the general condition currently labelled Red Pine Decline and Mortality. In some stands there was a strong tendency for trap catches to be particularly high near certain trees. Seasonal trends and sex ratios were compared with published reports of H. radicis activity in Michigan

Development of a linearized unsteady aerodynamic analysis for cascade gust response predictions

A method for predicting the unsteady aerodynamic response of a cascade of airfoils to entropic, vortical, and acoustic gust excitations is being developed. Here, the unsteady flow is regarded as a small perturbation of a nonuniform isentropic and irrotational steady background flow. A splitting technique is used to decompose the linearized unsteady velocity into rotational and irrotational parts leading to equations for the complex amplitudes of the linearized unsteady entropy, rotational velocity, and velocity potential that are coupled only sequentially. The entropic and rotational velocity fluctuations are described by transport equations for which closed-form solutions in terms of the mean-flow drift and stream functions can be determined. The potential fluctuation is described by an inhomogeneous convected wave equation in which the source term depends on the rotational velocity field, and is determined using finite-difference procedures. The analytical and numerical techniques used to determine the linearized unsteady flow are outlined. Results are presented to indicate the status of the solution procedure and to demonstrate the impact of blade geometry and mean blade loading on the aerodynamic response of cascades to vortical gust excitations. The analysis described herein leads to very efficient predictions of cascade unsteady aerodynamic response phenomena making it useful for turbomachinery aeroelastic and aeroacoustic design applications

A linearized Euler analysis of unsteady flows in turbomachinery

A method for calculating unsteady flows in cascades is presented. The model, which is based on the linearized unsteady Euler equations, accounts for blade loading shock motion, wake motion, and blade geometry. The mean flow through the cascade is determined by solving the full nonlinear Euler equations. Assuming the unsteadiness in the flow is small, then the Euler equations are linearized about the mean flow to obtain a set of linear variable coefficient equations which describe the small amplitude, harmonic motion of the flow. These equations are discretized on a computational grid via a finite volume operator and solved directly subject to an appropriate set of linearized boundary conditions. The steady flow, which is calculated prior to the unsteady flow, is found via a Newton iteration procedure. An important feature of the analysis is the use of shock fitting to model steady and unsteady shocks. Use of the Euler equations with the unsteady Rankine-Hugoniot shock jump conditions correctly models the generation of steady and unsteady entropy and vorticity at shocks. In particular, the low frequency shock displacement is correctly predicted. Results of this method are presented for a variety of test cases. Predicted unsteady transonic flows in channels are compared to full nonlinear Euler solutions obtained using time-accurate, time-marching methods. The agreement between the two methods is excellent for small to moderate levels of flow unsteadiness. The method is also used to predict unsteady flows in cascades due to blade motion (flutter problem) and incoming disturbances (gust response problem)

The Kansas Cattle Towns: Where Trail Meets Rail

Excerpt: That land of the West has gone now, gone, gone with lost Atlantis, gone to the isle of ghosts and of strange dead memories. It was a land of vast silent spaces, of lonely rivers, and of plains where wild game stared at the passing horseman .

Four Indian-Related Novels by Lucia St. Clair Robson

Excerpt: Lucia St. Clair Robson began publishing historical novels in 1982 with Ride the Wind, which draws on the history of the Comanches, and has continued to work in the field of historical fiction. Four of her novels focus closely on historical personages: Ride the Wind (Cynthia Ann Parker and Quanah Parker); Light a Distant Fire (Osceola of the Seminoles); Walk in My Soul (Tiana Rogers of the Cherokee and Sam Houston); and Ghost Warrior(Lozen of the Chiricahua Apache)

\u3cem\u3eThe Old Gringo \u3c/em\u3e and the Elegiac Western

The opening of The Old Gringo (1985), by Carlos Fuentes, sets in place the chief organizing principle of the novel, the narrated memories of Harriet Winslow, an unmarried schoolteacher from Washington, D. C., who, the reader discovers, once came to Mexico to instruct the children of the rich hacendado Miranda family and there became embroiled in the Revolution. Her contacts with the villista general Tomas Arroyo and the Old Gringo polarize her experiences between an apparent infatuation with Arroyo and an attempt to substitute the Gringo for her lost father. In her memories of the incidents which led her to place the body of the Old Gringo in her father\u27s empty tomb in Arlington, an elegiac tone — one of mourning for lost experience as well as a questioning of the value of that experience — is clearly discernible. Like the heroine of a classic Western film such as The Virginian (1929), Harriet, as the Eastern school marm character type, confronts the heroic Westerner, in this case doubled into the figures of the Old Gringo and Arroyo, and in the process re-examines her own preconceptions about civilization. She becomes conscious of her marginalization from the society around her, as an intellectual woman who questions her past and present. One concern of the discussion here will be the importance of the female perspective in the elegiac Western narrative: rather than a mere foil or pretext for the hero\u27s actions, the female character serves a critical function in clarifying the degree and nature of the hero\u27s loss of relevance in present-day society. The heroic figures themselves, the Old Gringo and Arroyo, can lay strong claim to kinship to the heroes (and villains) of Western film and fiction. Equally larger-than-life and ironically viewed, the Old Gringo has the superhuman marksmanship and courage of classic Western heroes such as the Ethan Edwards of John Wayne or the Shane of Alan Ladd. But he carries about him a cynicism and world-weariness which, though mirroring his real-life source in Ambrose Bierce, yet recall the elegiac musings of the aging gunfighters J. B. Books of The Shootist, Steven Judd of Ride the High Country, and Pike Bishop of The Wild Bunch

Mountain Men on Film

Excerpt: The mountain man of American folklore and history is a man between cultures. Like Janus, the doorkeeper god of the Romans, he is bifrontal, looking back at European, white civilization, and forward toward Indian civilization and culture

From the Iron Horse to Hell on Wheels: The Transcontinental Railroad in the Western

Excerpt: I\u27m crazy about trains! says Doc Holliday (Jason Robards) to his friend Wyatt Earp (James Garner) in Hour of the Gun (Sturges Ch. 6), explaining why he\u27s waiting on the Contention train. Of course he\u27s really there to help Earp get his revenge on Ike Clanton (Robert Ryan) - but then we never quite know with Doc Holliday